#7411: Exceptions are optimized away in certain situations -------------------------------------+------------------------------------- Reporter: SimonHengel | Owner: tdammers Type: bug | Status: new Priority: high | Milestone: 8.8.1 Component: Compiler | Version: 7.6.1 Resolution: | Keywords: seq, deepseq, | evaluate, exceptions Operating System: Linux | Architecture: x86_64 | (amd64) Type of failure: Incorrect result | Test Case: at runtime | simplCore/should_fail/T7411 Blocked By: | Blocking: Related Tickets: #5129 #15225 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by tdammers): New nofib results. - `nofib-gn-gnl`: GHC and boot libraries compiled with `-fno-state-hack` compiling nofib normally, vs. GHC compiled normally and boot libraries compiled with `-fno-state-hack` compiling nofib normally. This measures the effect of compiling GHC itself with `-fno-state-hack`. - `nofib-ns-nn`: GHC compiled normally compiling nofib normally vs. GHC compiled normally compiling nofib with `-fno-state-hack`. This measures the effect of the state hack on nofib when using a vanilla compiler. - `nofib-ns-nn-gnl`: GHC compiled normally with boot libraries compiled with `-fno-state-hack` compiling nofib normally vs. GHC compiled normally with boot libraries compiled with `-fno-state-hack` compiling nofib with `-fno-state-hack`. This measures the effect of the state hack on nofib when using a vanilla compiler with state-hack-free boot libraries. Key observations: - Differences are now much closer to what we expect, specifically, whether we compile GHC and / or boot libraries with or without the state hack does not significantly change nofib performance (< 1%). - Compiling GHC itself and boot libraries without the state hack makes nofib compilation slightly slower than compiling only boot libraries without the state hack (~4%). - Compiling nofib without the state hack makes compilation significantly faster (~25%) than compiling nofib with the state hack, regardless of how GHC itself and the boot libraries were compiled. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7411#comment:49 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler